One example of a known input device including a touch panel is described in Japanese Patent Application Publication No. 2012-118575 below. In the input device, an accelerometer detects quantity of vibration applied to the input device. If the quantity detected in a predetermined time period, which includes when the operating state of the touch panel or the press button changed, exceeds a predetermined value, the controller cancels the change in the operating state of the touch panel or the press button and maintains the initial operation state.
An object of the input device is to prevent an unintentional operation caused by an incorrect pressing operation resulting from vibration or impact. Thus, when the quantity of vibration applied to the input device while being subjected to vibration or impact, for example, is smaller than a predetermined value, the pressure applied by the pressing operation of the user is detectable. However, the detected pressure is affected by the quantity of vibration to some degree. The detection of the pressing operation may be improper.